\begin{tikzpicture}
    \tkzDefPoints{0/0/O}
    \tkzDefPoint(120:1.5){A}
    \tkzDefPoint(200:1.5){B}
    \tkzDefPoint(340:1.8){C}
    \tkzDefPointBy[translation=from B to C](A)  \tkzGetPoint{D}
    \tkzInterLC[common=A](A,D)(O,A)  \tkzGetFirstPoint{E}
    \tkzInterLC[common=B](B,C)(O,A)  \tkzGetFirstPoint{F}

    \tkzDrawCircle[thick](O,A)
    \tkzDrawPolygon(A,B,C,D)
    \tkzLabelPoints[above](A,E,D)
    \tkzLabelPoints[left](B)
    \tkzLabelPoints[right](C)
    \tkzLabelPoints[below](F)
\end{tikzpicture}

